If the post is edited and your tag is in the edit, you won't be alerted. (Also applies to quotes)
When a user is in the moderation queue if their post is edited it won't alert you. (If not edited it works fine, alert it sent after approval)
If merged, no alerts will be sent.

These are a few reasons, but it does seem that sometimes no alert is sent even when none of them reasons apply.

If the post is edited and your tag is in the edit, you won't be alerted. (Also applies to quotes)
When a user is in the moderation queue if their post is edited it won't alert you. (If not edited it works fine, alert it sent after approval)
If merged, no alerts will be sent.

These are a few reasons, but it does seem that sometimes no alert is sent even when none of them reasons apply.

@mcdorli What he's saying is that they are using an outdated addon, this can be updated by Curse. The newest versions and other addons have these issues fixed. I'm not actually sure the last time Tag Me was updated.

@mcdorli What he's saying is that they are using an outdated addon, this can be updated by Curse. The newest versions and other addons have these issues fixed. I'm not actually sure the last time Tag Me was updated.